Another San Diego premiere, another “tough” piece, another exploration of the mystery of identity — that’s business as usual at Ion Theatre, which this week opens Craig Wright’s poetic shocker, “Grace,” at its Hillcrest storefront.

“We tend to do pieces that are tough in that they explore issues that people are interested in: They’re provocative, edgy, sometimes difficult,” says Glenn Paris, Ion’s producing artistic director who is directing the four-person play.

“When I was in grad school at Carnegie Mellon, I did my thesis on (iconoclast Jean) Genet. It was called ‘Exploding Identity.’ And it’s relevant to Wright’s play. In this society, we live in fear, and that can make some people turn to religion — or buy a gun.”

Wright, a successful television writer (“Six Feet Under”) and former seminarian, based his play upon a real-life crime committed in a Florida condo by an unlikely man. The gripping, intermissionless action unfolds backward in time and engages many themes, one of which is of special interest to Paris: the intersection of faith and science.

“So many of us feel spiritually bereft,” he says. “Yet our lives are so busy we hardly take a breath to grapple with our own crises let alone keep up with science. It’s easy to understand why people turn to the church and have made it such a powerful force in society.”

Institutional religion too often separates itself from science, he says, and “Wright is making an interesting argument in the play that this particular character (Steve) has made that separation and for him spirituality is corporate Christianity, not social justice, or a sense of how spirituality and science can enrich one another.”

Aside from its themes, says Paris, “Grace” possesses an innovative structure that drew him and Ion partner Claudio Raygoza to the script. “We read so much conventional writing, and this was different, with powerful tight scenes in one setting, though the time structure moves about. One of the things that can challenge a small theater like ours is when playwrights have multiple scenes, 15 or 20 of them in different settings if they are used to writing for TV. We’re grateful when we find a script that’s different.”

Paris says he’s thrilled with his cast, which includes the volcanic actor Francis Gercke as Steve, Rhianna Basore as his wife Sara, Nick Kennedy of Poor Players as the disfigured neighbor Sam who befriends her, and Jim Chovick as a German-born exterminator with tales of his own to tell.

Acknowledging that the award-winning Ion has been on a roll this season and last, Paris says: “We have expanded by half a dozen artists in the last few months — we’re calling our associates members of the company. Our season is quite aggressive (in quantity of shows and unflinching themes). And people seem to love the intimacy of our space, which we will open up and bring closer than ever to the audience for ‘Grace.’ ”